Around twelve million people file self assessment returns each year, and London supplies a disproportionate share: directors and shareholders, landlords, freelancers, high earners past the £100,000 threshold, and internationally mobile professionals whose returns stop being simple the moment they arrive. The 31 January deadline is unforgiving, and the cost of errors - penalties, interest, or simply overpaying - lands entirely on the taxpayer.
London's market for help runs from boutique personal tax practices to substantial firms with dedicated private client teams. The better providers do more than transcribe figures: they claim the reliefs, plan ahead of the tax year end, and handle HMRC so their clients never have to.
This guide highlights a selection of self assessment tax return services companies in London. It is not a ranking - the aim is context on who each firm is and the kind of taxpayer they serve best.
Acumon
Acumon is a London firm of chartered accountants, based in Ealing, whose personal tax practice prepares self assessment returns as tax advisors rather than typists - with many of the team's qualified advisors having previously worked for HMRC and a Chartered Tax Advisor in-house. Returns are prepared early enough that January becomes just a payment date, with payments on account explained and managed rather than left to ambush clients in July.
The practice handles the situations where self assessment gets genuinely complicated: capital gains including the 60-day property reporting deadline, landlord income under the finance cost restriction, directors' dividend and benefit reporting reconciled with their companies' records, and foreign income. Fees are fixed and agreed in advance, and if HMRC opens an enquiry into any return, the firm's tax investigation specialists take over the correspondence.
Key Highlights:
- Many of the firm's qualified tax advisors previously worked for HMRC
- In-house Chartered Tax Advisor (CTA), qualified by the Chartered Institute of Taxation
- All 90 of the firm's professionals are based in the UK
- Handles 60-day property returns and complex CGT reporting alongside self assessment
- Fixed fees agreed in advance
Services:
- Self assessment tax return preparation and filing
- Personal tax planning reviews before the tax year end
- Capital gains tax and 60-day property returns
- Landlord and property income reporting
- Director and shareholder personal tax
- HMRC correspondence and enquiry support
Contact Information:
- Website: acumon.com
- E-mail: [email protected]
- Address: 1-2 Craven Road, Ealing, London, W5 2UA, UK
- Phone: 020 8567 3451
Warrener Stewart
Warrener Stewart operates from Harwood House in Fulham, with a second office in Edinburgh, and brings genuine tax depth to personal returns: the team includes Chartered Accountants, Chartered Tax Advisors and Registered Auditors, with named personal tax specialists holding CTA and ATT qualifications. Its self assessment service is comprehensive - HMRC registration, information gathering from banks and financial institutions, liability calculation, completion and filing.
The client base is distinctly south-west London: business owner-managers, UK subsidiaries of foreign companies and private individuals concentrated around Fulham, Chelsea, Hammersmith, Kensington, Knightsbridge and Mayfair. Deadlines are tracked for clients and tax-saving recommendations made as part of the service, with buy-to-let, IHT, trusts, Making Tax Digital and a dedicated US tax service extending the range.
Key Highlights:
- CTA and ATT qualified personal tax specialists
- Full service from HMRC registration to filing
- South-west London private client heartland
- Dedicated US tax service
- Tax-saving recommendations built into the return work
Services:
- Self assessment tax returns
- Personal tax planning
- Buy-to-let / landlord tax
- IHT, trusts and estates
- Making Tax Digital support
- US tax services
- Audit and assurance
- VAT, payroll and bookkeeping
Contact Information:
- E-mail: [email protected]
- Address: Harwood House, 43 Harwood Road, Fulham, London, SW6 4QP
- Phone: 020 7731 6163
Gerald Edelman
Gerald Edelman brings scale to personal tax: a City firm with around 80 years of history, over 4,000 clients, and a tax team of more than 25 advisers whose backgrounds run from ex-HMRC inspectors to dual-qualified Chartered Tax Advisers and Chartered Accountants. Self assessment compliance is managed as part of a broader personal tax relationship.
That breadth matters for complex affairs: capital gains, inheritance tax, international questions, offshore trusts, property tax and tax investigations are all handled in-house, with estate planning, probate and wealth management available through the firm's private client practice. For high earners whose returns touch several of those areas at once, having one team across all of them is the point.
Key Highlights:
- Tax team of 25+ including ex-HMRC inspectors
- Around 80 years of history and 4,000+ clients
- Offshore trusts and international expertise
- Tax investigation support in-house
- Estate planning and probate available
Services:
- Self assessment tax compliance
- Personal tax advisory
- Capital gains tax
- Inheritance tax and estate planning
- Property tax
- International tax and offshore trusts
- Tax investigations
- Audit, accounting and payroll
Contact Information:
- E-mail: [email protected]
- Address: 73 Cornhill, London, EC3V 3QQ
- Phone: +44 (0)20 7299 1400
Coman & Co
Coman & Co is the boutique model done properly: Chartered Certified Accountants and Chartered Tax Advisers formed in Dulwich in 2009, where principal Ray Coman handles clients personally. Tax return preparation covers the full spread - self-employment, investment income, pensions and employment earnings - for a clientele that skews toward high income, top rate and additional rate taxpayers working in central London.
The practice pairs return work with the property expertise London taxpayers most often need: landlord tax services, property capital gains advice, and HMRC investigation support when returns are questioned. QuickBooks and Xero certifications cover the software side, and the single-principal model guarantees the continuity larger firms can only promise.
Key Highlights:
- Principal-led service - clients dealt with personally
- Chartered Tax Adviser and Chartered Certified Accountant
- High-earner and additional-rate taxpayer focus
- Landlord and property CGT expertise
- South London base, central London clientele
Services:
- Self assessment tax returns
- Landlord tax services
- Property capital gains tax
- Contractor and limited company accounting
- Company tax returns
- Tax planning and advice
- Payroll outsourcing
- HMRC tax investigation support
Contact Information:
- Address: The Gallery, 14 Upland Road, East Dulwich, London SE22 9EE
- Phone: 0208 2991575
Fusion Accountants
Fusion Accountants, an ICAEW member firm and Xero Platinum Partner with offices serving Hounslow, Brentford, Harrow, Kingston and East London, has built its self assessment service for the capital's self-employed: sole traders, freelancers, landlords, partnerships and investors. The firm acts as registered tax agent with HMRC, handling all communications on clients' behalf.
Pricing is unusually explicit for London - self assessment from £12.50 plus VAT per month - and the service is positioned as value-add rather than number crunching, with UK-based dedicated accountants and cloud integration across Xero, QuickBooks and FreeAgent. For freelancers and landlords who want a fixed, low monthly cost with a real firm behind it, the offer is straightforward.
Key Highlights:
- Self assessment from £12.50+VAT per month
- Registered HMRC tax agent handling all communications
- ICAEW member firm and Xero Platinum Partner
- Built for freelancers, sole traders and landlords
- Offices across west and east London
Services:
- Self assessment tax return preparation and filing
- Tax advisory and planning
- HMRC agent services and correspondence
- Sole trader and freelancer accounting
- Landlord tax returns
- Partnership tax returns
- Cloud accounting (Xero, QuickBooks, FreeAgent)
Contact Information:
Naail & Co
Naail & Co, Chartered Certified Accountants on Lambeth Walk, specialise in the preparation and submission of personal self assessment returns with service standards most firms would not put in writing: same-day response to all email enquiries and direct line access to a dedicated Accounts Manager for every client. The office is paperless, with the firm's own mobile app.
Returns sit within a broader tax capability - capital gains, inheritance tax, R&D credits and business restructuring - and software partnerships span Xero, QuickBooks and Sage. The combination of boutique responsiveness and full-service range suits taxpayers who want their questions answered today, not at month-end.
Key Highlights:
- Same-day response to all email enquiries
- Dedicated Accounts Manager with direct line access
- Paperless office with its own mobile app
- CGT, IHT and R&D capability alongside returns
- Central London base on Lambeth Walk
Services:
- Personal self assessment tax returns
- Tax planning and advice
- Capital gains tax
- Inheritance tax
- Bookkeeping and VAT
- Payroll services
- Company accounts and tax
- R&D tax credits
Contact Information:
- E-mail: [email protected]
- Address: 69-71 Lambeth Walk, London SE11 6DX
- Phone: 020 3333 3000
Bryden Johnson
Bryden Johnson has been serving London from Croydon for over 125 years - an ICAEW accredited firm and Xero Gold Partner whose personal tax service centres on prompt completion of self assessment returns with planning and HMRC liaison built in. The firm's longevity is its own reference: south London businesses and families have filed through it for generations.
Clients span established, high-growth and start-up organisations across Croydon, South London and Surrey, and the personal tax work connects naturally to the firm's business services - accounts, audit, business tax, payroll and digital accounting - for directors whose personal and company affairs are two halves of one picture.
Key Highlights:
- Over 125 years of continuous practice
- ICAEW accredited and Xero Gold Partner
- Personal tax planning and HMRC liaison included
- South London and Surrey heartland
- Business services for director clients
Services:
- Self assessment tax returns
- Personal tax planning
- HMRC liaison
- Business tax
- Accounts preparation
- Audit and compliance
- Payroll
- Digital accounting
Contact Information:
- E-mail: [email protected]
- Address: Kings Parade, Lower Coombe Street, Croydon, CR0 1AA
- Phone: 020 8686 0255
Unicorn Accountants
Unicorn Accountants files personal tax returns and handles compliance from Merchant Square in Paddington, with an emphasis on straightforward advice that keeps clients compliant while easing the tax burden. The firm works with a large number of SMEs, which shapes its personal tax clientele: directors, shareholders and owner-managers whose returns interlock with company affairs.
For complex situations the personal tax expertise runs deep - capital gains, inheritance tax, trusts and estates, and international and cross-border matters - with real estate tax planning and tax investigation relief completing the range. Cost-effective handling of complex queries is a stated priority, backed by the firm's strong client relationships.
Key Highlights:
- Personal returns interlocked with SME company affairs
- CGT, IHT, trusts and cross-border expertise
- Real estate tax planning available
- Tax investigation and dispute relief
- Paddington base serving the whole capital
Services:
- Personal tax return filing and compliance
- Tax planning and consulting
- Capital gains tax advice
- Inheritance tax guidance
- Trusts and estate advisory
- Real estate tax planning
- International and cross-border tax advisory
- Tax investigation and dispute relief
Contact Information:
- E-mail: [email protected]
- Address: 5 Merchant Square, London W2 1AY
- Phone: 020 8064 0454
Conclusion
The right self assessment provider in London depends on what your return actually contains. A freelancer with one income stream needs accuracy, speed and a sensible fixed fee; a director, landlord or internationally mobile professional needs advisors who plan ahead of the year end and can defend the return if HMRC asks questions. Both ends of that spectrum - and everything between - are well served in the capital.
This guide was compiled to shortcut the search. Whoever you engage, the habits that mark out a good personal tax firm are consistent: returns prepared months before the deadline, payments on account explained before they surprise you, reliefs claimed rather than merely recorded, and HMRC handled entirely on your behalf. January should be a payment date, not an ordeal.
